Diterpenoids from Callicarpa kwangtungensis and their NO inhibitory effects

A phytochemical investigation of the leaves of Callicarpa kwangtungensis led to the isolation of three new diterpenoids (1-3), callipenes A-C, and eleven known analogues (4-14). Their structures were established on the basis of extensive analysis of NMR spectroscopic data, X-ray diffraction data, and experimental and calculated electronic circular dichroism spectra. Compounds 1 and 2 are rare abietane diterpenoids possessing a peroxide bridge. All of the isolates were found to inhibit LPS-induced NO production in BV-2 cells. (C) 2016 Published by Elsevier B.V.